1. Field of the Invention
The present invention relates to a clutch in a mechanical driving device, and more particularly, to an eccentric gearing type clutch for power transmission by taking advantage of the eccentric principle.
2. Background of the Related Art
A clutch is widely used in a mechanical driveline for power transmission, more particularly in automobiles utilizing an internal combustion engine, and it is mainly used to transmit the power from a driving machine to a driven machine for convenient manipulation of the driven machine. In the entire driving system of an automobile, as one of the main parts thereof, the clutch is arranged at the front end and used frequently during the driving of the automobile.
The existing clutches include gear clutches, friction clutches, hydraulic clutches, electromagnetic clutches, and the like.
A conventional friction clutch operates based on friction, the heat generated during frequent usage leads to the rise in temperature of the pressure plate, flywheel and other components of the clutch, which accelerates wear out of the friction disc and shortens the lifespan of the clutch, such that the heat dissipation of the entire clutch needs to be improved. Further, the braking of the friction clutch is not precise; among other things, an instant braking of a large machine could hardly be implemented.
An existing hydraulic clutch transmits torque via an operation oil (fluid oil), the housing of the clutch is integrated with the pump wheel as a drive member; in contrast, the turbine is a driven member; when the rotation speed of the pump wheel is relatively slow, the turbine will not be driven, such that the drive member and driven member are in a disengaged state; as the rotation speed of the pump wheel increases, the turbine will be driven and the drive member and driven member are in an engaged state. The braking performance of such a machine utilizing the pump wheel and turbine for power transmission is also not precise, and the loading capacity of the machine is limited.
An electromagnetic clutch is a clutch that is engaged and disengaged by powering on and off an electric coil. By putting some magnetic powders between the drive member and driven member, the engagement force will be enhanced, and such a clutch is called a magnetic particle clutch, which is relatively high in energy consumption and manufacturing cost, uneconomical, and could not be promoted and used extensively.
In recent years, new attempts have been made to improve clutches. For example, PRC patent ZL200510119050.2 discloses a pump type hydraulic clutch, which adopts an inner gearing of a pinion and a large gear ring. The pinion is coaxially rotatably connected in the housing, a crescent separator board is arranged in the pinion and the large gear ring, in such a manner that a high pressure oil cavity and a low pressure oil cavity are respectively formed between the pinion, large gear ring, crescent separator board and housing. An operation oil is filled into the high pressure oil passage and low pressure oil passage via oil inlets, and the engagement and disengagement operations are controlled by pressure valves connected with respective oil passages. Although the clutch of this PRC patent is an improvement to conventional clutches and has the advantages of being high in transmission efficiency, small in volume, low in manufacturing cost, and so on, however, as it transmits power via gear engagement, the frictional force between the gears will lead to the wear out of various degrees, which affects the surface quality of the gears and shortens the lifespan of the entire clutch.
U.S. Pat. No. 3,974,900 discloses a rotary displacement mechanical coupling device, which also utilizes gear engagement for power transmission thereby having also the foregoing defects.
U.S. Pat. No. 4,924,989 discloses an automatic clutch control system for coupling two rotating shafts, which also utilizes gear in control of the rotation torque, wherein it comprises a friction disc, a pinion and the like, whereby the defects as those in the prior art unavoidably exist.
In view of the various defects in the foregoing clutches, there is a need for a new type of clutch which is safe and stable in operation, good in brake performance, long in lifespan, free of surface wear, simple in configuration, and low in power consumption.
An object of the present invention is to overcome the above defects by providing an eccentric gearing type clutch which is long in lifespan, simple in manipulation, good in reliability, capable of instant braking, and excellent in heat dissipation.